发明名称 |
DIGITAL MODULATION CIRCUIT |
摘要 |
A modulator circuit for generating a modulated, DQPSK signal. The modulator circuit includes an encoder for receiving a binary bit stream comprised of bit pairs defining differential phase changes. An encoder receives a bit stream of which bit pairs thereof define differential phase changes. The encoder encodes the bit pairs into codewords which are stored and then supplied to an I-accumulator, a Q-accumulator, and a memory element. The memory element contains pre-multiplied values which are supplied to the I- and the Q-accumulators which add terms of the pre-multiplied values to form I-portions and Q-portions of a DQPSK-modulated signal. The I- and Q-portions may then be supplied to a quadrature modulator.
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申请公布号 |
US5157693(A) |
申请公布日期 |
1992.10.20 |
申请号 |
US19910678518 |
申请日期 |
1991.04.01 |
申请人 |
MOTOROLA, INC. |
发明人 |
LEMERSAL, JR., DONALD B.;WALCZAK, THOMAS J.;GREENE, ROBERT J. |
分类号 |
H04L27/20 |
主分类号 |
H04L27/20 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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